In retrospect, it seems odd that Lorne Greene -- the Lorne Greene, from Bonanza -- was part of Battlestar Galactica. After all, Bonanza’s Ben Cartwright doesn’t seem like the kind of guy who’d hang out with Richard Hatch or Dirk Benedict, who make those ridiculous faces while shooting laser guns. But then, when you learn that Greene’s real name is exactly the sort of name you might associate with a sci-fi geek -- he was born Lyon Chaim Green in Ontario, Canada -- things suddenly make a lot more sense. Learn more about Battlestar old and new inside this section.

[dl] TelevisionBattle On

Battlestar Galactica’s surprisingly successful resurrection comes to an end this month. For those who’ve missed the show so far, now is the time to catch up -- before it’s too late.

Remaking old television shows is dicey. Not all once-popular series will reconnect with today’s audience. Take Bionic Woman, for example. That revived NBC show’s big initial audience evaporated in the weeks after the premiere last fall. Perhaps viewers were turned off by the reimagined Jamie Sommers -- an angry single woman raising her kid sister. Or maybe they just didn’t like the fact that Sommers’s bionic moments weren’t accompanied by that weird mechanical sound effect featured in the original show. And therein lies the challenge for the producers of remade shows: What to keep? What to scrap? If you remake American Gladiators, do you keep the ridiculous spandex outfits? Yes. And if you remake Battlestar Galactica, do you keep the handsome fighter pilot Starbuck, with the feathered hair and swaggering manner? Well, no. Not quite.

When the Sci Fi Channel relaunched the 1978 Battlestar Galactica series in 2004, it cast a woman to play Starbuck. She’s got the swagger but not the feathered hair. And this complex Starbuck is far removed from her one-dimensional male counterpart. So, too, the entire series is removed from its earlier counterpart. The new Battlestar Galactica has wooed new disciples and converted devotees of the classic series (which aired for just one year) by keeping the core premise of the original show but improving on it with more interesting characters and more dazzling special effects. That approach has drawn a legion of fans to Sci Fi and has engendered rave reviews from numerous critics. Still, you could be forgiven for having missed all the hubbub over Battlestar and even its first few seasons. Sci Fi certainly doesn’t have the marketing muscle of a bigger network, and Battlestar’s audience, while big for cable television, is about a tenth of the size of the Desperate Housewives audience. That’s where we come in. This month, the fourth season -- and what has been promised to be the final season of the new Battlestar -- premieres on Sci Fi. So if you haven’t caught it yet, we offer this quick guide on the evolution of Battlestar Galactica, from the old to the new, plus a few things you need to know in order to enjoy season four.

THE LOOK AND FEEL

OLD BG: Glen A. Larson was the executive producer of the 1978 series. He was also executive producer of Magnum P.I., The Fall Guy, Knight Rider, and Buck Rogers in the 25th Century. So it makes sense that the original Battlestar starred dashing heroes (with feathered hair), like Richard Hatch as Captain Apollo and Dirk Benedict (“Faceman” from The A-Team) as Lieutenant Starbuck. It also featured cute robot dogs and even cuter kids. Plus, there were more than a few warriors running around in spandex outfits that would have been right at home on the aforementioned American Gladiators.

NEW BG: The current Battlestar’s executive producer is Ronald D. Moore, who also helmed Star Trek: Deep Space Nine and HBO’s edgy Carnivàle. While, yes, there are plenty of lookers in the cast, the new show offers more grit than sizzle. The fleet is often shown suffering under the pressure of their fight for survival. Haggard characters deal with real-world problems like alcoholism, class warfare, and political upheaval.

ONE NEW THING YOU NEED TO KNOW: The new Battlestar’s core plotline is essentially the same as the original series’. There are 13 human colonies (all planets). In the original Battlestar, Cylons are a race of alien cyborgs. In the current Battlestar, the humans on these planets created the Cylons. In both series, the Cylons turned on the humans and destroyed 12 of the colonies. Now, left with a mother ship called the Galactica and a fleet of smaller ships, the humans are in search of the one remaining planet -- one they aren’t even sure exists outside mythology. It’s called Earth. Sounds familiar.

THE CYLONS

OLD BG: The Cylons were robotic alien cyborgs fitted with Darth Vader–like masks that were a shiny silver. They had Knight Rider–like LED eyes that ping-ponged from one side to the other. They looked cool, but as characters, they were about as exciting as storm troopers.

NEW BG: The current Cylons are Terminator-like cyborgs who can take human form. Indeed, the best-looking member of the cast may be a Cylon named Number Six. She’s played by former runway model Tricia Helfer.

ONE NEW THING YOU NEED TO KNOW: Several Cylons have infiltrated the Galactica fleet in the past three seasons. Many were sleeper agents who didn’t even know they were clones of actual humans until their programming was switched on and their mission was revealed to them. So, the final season’s biggest questions are: How many more unmasked Cylons are left? Who are they?

COMMANDER ADAMA

OLD BG: The Galactica’s leader, Commander Adama, was played by Lorne Greene. Adama was troubled yet calm, wise, and fair.

NEW BG: The current Adama, as played by Edward James Olmos, is certainly troubled. Weary, even. But unlike Greene’s character, Olmos’s doesn’t always do what seems fair or wise or popular. In one episode, he decides to destroy a civilian ship -- and its crew -- because the Cylons may have taken control over it.

ONE NEW THING YOU NEED TO KNOW: In the new series, Commander Adama’s son, Lee, is sometimes called Apollo, a reference to Captain Apollo of the original series.

RICHARD HATCH

OLD BG: The star of the original series took his clothes off a lot and won a million bucks at the season’s end. No, wait -- that’s a different Richard Hatch. This Hatch actually starred as Captain Apollo, the handsome, tough leader of the fleet’s pilots.

NEW BG: Hatch had long hoped for the development of a Battlestar Galactica that would pick up where the 1978 series left off (meaning he’d hoped to be cast as an older Captain Apollo who’s still looking for Earth). Instead, he was cast in the Sci Fi series as a jailed political activist named Tom Zarek, who eventually is released from his prison barge and goes on to pursue the presidency of the surviving humans.

ONE NEW THING YOU NEED TO KNOW: Mary McDonnell, who plays the president, is one of a slew of tough, powerful women in the Battlestar cast, which includes Katee Sackhoff as Starbuck and Grace Park as Boomer.

THE CLIFF-HANGERS

OLD BG: The show lasted just one full season, with 17 total episodes airing. No ratings champion, it was canceled without a satisfying series-ending episode -- the ultimate cliff-hanger.

NEW BG: Each season has unveiled memorable cliff-hangers. The first season ended with the attempted assassination of Commander Adama by Boomer, who was revealed to be a Cylon. The second season ended with the humans being trapped by and living under Cylon rule on a planet dubbed New Caprica. Baltar (whom we think is a traitor -- maybe) was sworn in as president, while Adama escaped with the Galactica to plot a rescue mission.

ONE NEW THING YOU NEED TO KNOW: The most important of the cliff-hangers is arguably the most recent of them. The third season ended with Starbuck unexpectedly returning from the brink of death and promising that she can now lead the beleaguered human fleet to Earth. But her near-death experience has led fans to wonder whether this Starbuck is actually a Cylon clone. (Cue dramatic music.)